1. Field of the Invention
The present invention relates to a power storage element, a manufacturing method of the power storage element, and a power storage device.
A power storage element in this specification refers to any element which has a function of storing power, and a power storage device in this specification refers to any device which has a function of storing power and in which a plurality of power storage elements are arranged in a plane.
2. Description of the Related Art
In recent years, a variety of power storage devices such as lithium secondary batteries, lithium-ion capacitors, and air cells have been developed. In particular, a lithium secondary battery in which charge and discharge are performed by transfer of lithium ions between a positive electrode and a negative electrode has been attracting attention as a secondary battery with high output and high energy density.
A lithium secondary battery refers to a secondary battery where lithium ions are used as carrier ions. Examples of carrier ions which can be used instead of lithium ions include alkali-metal ions such as sodium ions and potassium ions; alkaline-earth metal ions such as calcium ions, strontium ions, and barium ions; beryllium ions; and magnesium ions.
Many of conventional electrolytes of lithium secondary batteries are liquid electrolytes which have high lithium conductivity at room temperature, and organic electrolytic solutions are used in many of commercially available lithium secondary batteries. However, lithium secondary batteries which contain organic electrolytic solutions have risks of leaking the electrolytic solutions and catching fire; therefore, an all-solid-state battery which contains a solid electrolyte and has a high level of safety has been actively researched (see Patent Document 1).
Further, there is a technique where a plurality of solid batteries are stacked, high operating voltage can be obtained when they are connected in series and discharged, and they are individually charged when they are connected in parallel and charged (see Patent Document 2).